《区块链项目开发指南》读书笔记4

第4章 开始使用web3.js

1. web3.js目前已经到1.0.0-beta18
2. 接上一章交互控制台继续试验

console.log(web3.eth.gasPrice.toString());

因为本机刚开始挖矿，gas价格是1

3. 查看余额（因示例的45区块太大，修改第二个参数“区块”为2）

console.log(web3.eth.getBalance("0x1628cb0fE5e3fFE930C4Fb13Ba3C0d032DD6cadE",2).toString());

第一个参数是地址

4. 查看交易细节（无法打印对象，但可以直接输出）

web3.eth.getTransactionReceipt("0x3fc10b7326cc5f4211ac6c665c3370b2d00a1b433659cfb1e48da8d0b884ae01");

输出类似如下形式

{
  blockHash: "0x47c72a27d214838de126ca4057e5760ae45ab5e285104eddde2b9b958646938a",
  blockNumber: 1,
  contractAddress: "0xf095b1932ee9e6424b328bdf518d617503c7c0f7",
  cumulativeGasUsed: 574693,
  from: "0x1628cb0fe5e3ffe930c4fb13ba3c0d032dd6cade",
  gasUsed: 574693,
  logs: [],
  logsBloom: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  status: "0x1",
  to: null,
  transactionHash: "0x3fc10b7326cc5f4211ac6c665c3370b2d00a1b433659cfb1e48da8d0b884ae01",
  transactionIndex: 0
}

参数为交易号，而非帐户地址。

5. 章节4.1.9的程序代码，感谢简述的Solidity高亮

var event = proof.logFileAddedStatus(null, {
    fromBlock: 0,
    toBlock:"latest"
});
event.get(function(error, result){
    if(!error)
    {
        console.log(result);
    }
    else
    {
        console.log(error);
    }
});
event.watch(function(error, result){
    if(!error)
    {
        console.log(result.args.status);
    }
    else
    {
        console.log(error);
    }
});
setTimeout(function(){
    event.stopWatching();
}, 60000);
var events = proof.allEvents({
    fromBlock: 0,
    toBlock: "latest"
});
events.get(function(error, result){
    if(!error)
    {
        console.log(result);
    }
    else
    {
        console.log(error);
    }
});

event.watch(function(error, result){
    if(!error)
    {
        console.log(result.args.status);
    }
    else
    {
        console.log(error);
    }
});
setTimeout(function(){
    event.stopWatching();
}, 60000);